1. Field of the Invention
The present invention relates to a system of electronic reprographics and, more particularly, to a method and apparatus for recording and diagnosing faults in an electronic reprographic system.
2. Description of the Related Art
In electronic reprographic printing systems, a complex series of interactions occurs between the software services and objects and the hardware functions to provide the printed or otherwise processed end-product. In such a system, a document or series of documents comprising at least one print job are successively scanned, resulting in image signals which are electronically stored. The signals are later read out successively and transferred to a printer for formation of the images on paper. Such a document can be printed any number of times or processed in any number of ways (e.g., words deleted or added; image magnified or reduced, etc.). If a plurality of documents comprise a job which is being processed, the processing or manipulation of the documents can include deletion of one or more documents, reordering of the documents into a desired order, or addition of a previously or subsequently scanned document or documents. The printing or processing can be relatively synchronous with scanning, or asynchronous after scanning. If asynchronous, a time interval exists between scanning and printing or processing. The system can then accumulate a number of scanned jobs in the system memory for subsequent processing or printing. The order of the jobs to be printed may be different from the order of jobs as scanned depending on the priority of the jobs and the desires of the operator for increasing productivity or through-put and decreasing printer or scanner down-time.
In such a system, faults on all levels of functioning can occur. Software object faults may occur to result in such problems as illegal job parameters, corrupted data, resource problems, input master errors, font problems, etc. Mechanisms for dealing with such faults are an integral and necessary component of the system, because such faults will result in the interruption of the system, and may result in a crash of the system which requires that the system be rebooted Information from the system provided to the operator directing the operator to the fault or faults causing the job interruption is critical to the efficient operation of the system.
The related art has disclosed printing systems with automatic online diagnostic ability for an electronic copier which is activated after a severe fault exceeds a threshold.
U.S. Pat. No. 4,133,477 to Marino et al. discloses a xerographic type copying machine having a fault detection system. Fault flag arrays are associated with each machine component for recording certain faults and machine operation.
U.S. Pat. No. 4,739,366 to Braswell et al. discloses a diagnostic system in a reprographic machine provided with stored optimum operating parameters against which actual operating characteristics may be compared for a determination of repair or adjustment requirements. Event information may be accessed graphically or numerically to show the history of the machine's operation.
U.S. Pat. No. 3,838,260 to Nelson discloses a microprogrammable control memory diagnostic system. Fault information and the status of the system at the time of a fault are stored in memory and enable diagnostics which read out the faulted information.
U.S. Pat. No. 4,499,581 to Miazga et al. discloses a self-testing system for a reproduction machine incorporating self-test routines to test the machine operating logic to insure the integrity and operability of the component parts of the operating logic. A display panel visually identifies any fault to facilitate repair and servicing.
U.S. Pat. No. 4,691,317 to Miazga et al. discloses a method of deselecting features of a xerographic machine to be able to continue operation of the machine even though a fault has been detected, by isolating a detected malfunction to a particular input or output, determining that the particular input or output is related to a specific machine feature, and instructing the operator to deselect that feature for continued machine operation. In the event that the isolated fault is related to a machine feature not selected for the particular job, the fault is ignored.
U.S. Pat. No. 4,477,178 to Furuichi et al. discloses an image forming apparatus having detection devices for detecting trouble in the process unit, and circuitry for preventing image forming operation in response to the detection of a problem by the detection devices.
U.S. Pat. No. 4,633,467 to Abel et al. discloses a computer system fault recovery method which generates error reports in response to detection of error conditions. When a report is received, a list is generated containing probable fault weights for each type of error. A history list of faults is aged and combined with the list to select the most probable fault unit.
While the related art provides for the detection and recording of faults in order to create a history from which an analysis can be made of the faults, the prior art fails to disclose a centralized fault logging service within the system which is used to trigger different specific actions depending on the faults logged, or an online diagnostic which can verify and/or isolate a suspected problem.